1. Field of the Invention
The present invention relates to electrical sockets, and in particular, to a socket having a base with a plurality of receptacles surmounted by a sliding plate having matching holes.
2. Description of Related Art
Electrical components are often mounted in sockets employing spring contacts. These sockets allow easy installation and replacement of electrical elements. In conventional sockets the pins of an integrated circuit (IC) are pressed into a socket to deflect the spring contacts.
Modern integrated circuits are fairly complex and have a large number of dependent pins. While the force required to insert an individual pin into a socket receptacle may be modest, simultaneously inserting a large number of pins can require a large insertion force. Such large insertion forces may damage the IC or bend its pins.
U.S. Pat. No. 4,887,974 shows in its FIGS. 1A and 1B, cantilevered contacts mounted in a base. A sliding grid mounted over the base guides the dependent pin of an electrical element. The grid is initially aligned so the pins can be inserted through the grid without touching the electrical contacts in the base. Thus, the pins can be inserted with zero insertion force. After the pins are thus inserted, the grid can be shifted relative to the base to drive the pins against the cantilevered contacts, which then deflect. These cantilevered contacts have a vertical branch and a relatively short transverse branch for touching the pin.
U.S. Pat. No. 5,013,256 shows another electrical socket whose base has a number of receptacles containing electrical contacts. The base is overlaid with another sliding grid. The socket contains a compression or torsion spring that is tensioned when the grid slides the pins against the electrical contacts in the receptacles. Thus, the spring is designed to urge the pins away from the contacts in the receptacles. The connection, however, is maintained by a lever that overcomes the spring and drives the grid to the engaged position.
U.S. Pat. No. 4,420,205 shows a similar socket in which the grid is slid relative to the base by means of a cam that can be rotated by a screw driver.
A disadvantage with sockets of this type is the need for the electrical contacts to be flexible, i.e. springy. This flexibility requires a relatively thin contact (or high operating force) as well as sufficient room to deflect.
See also U.S. Pat. Nos. 4,343,524; 4,350,402; 4,391,408; 4,519,660; 4,713,020; 4,744,768; 4,836,798; 4,846,713; 4,889,499; and 5,186,642.
Accordingly, there is a need for an improved zero insertion force socket that avoids such disadvantageous requirements as substantial deflection of the electrical contacts mounted in a base.